I went for Beru ones from Euro Car Parts. Kinda just went with the 'pick the middle one' way of shopping :) http://www.eurocarparts.com/ecp/c/Ford_Focus_1.8_2006/p/car-parts/car-service-parts/regular-service/glow-plugs/?438580045&1&50a37e8be93efe339d5c8c5bf0c3d75bb80db9d7&000164 By the way, I used the discount code ALL20 to get 20% off. Not sure if it's still available though

Hi folks. Quick status report. So, I initially took a look at the engine and being a total engine noob, I bailed and then enlisted some assistance from my uncle who had every single ratchet piece on the planet. I tell you, he's got parts big enough to spin the planet itself, and parts small enough to perform microsurgery. In Metric and Imperial! Anyway, in the end the job was indeed fairly simple although quite fiddly. We didn't have to remove anything except the plugs themselves. We found even the rightmost plug was easy enough to remove if you have the right angular ratchet bits to get in behind the dipstick holder. Catching the small 6mm screws that hold the plate to the plug was harder than removing the plugs themselves. It just took some dexterity of the fingers to catch them as they reached the end of the thread. One tip I can offer is that I had in my toolkit an extendable magnetic pickup tool. This was ideal for getting the screws back on again as I could pop them on the end of the tool and get them started on the thread before switching to fingers and ratchet. But now the important result. Replacing the glow plugs did indeed cure my starting problem. Admittedly I haven't had a very cold day since they were replaced - it's cold, but not freezing - but starting has been smooth as a smooth thing so far. I'm happy with the result. What annoys me is I had the car serviced and told them of the specific issues. No fix. In fact, the garage claimed there was a rattle from near the fuel pump or water pump and I should see a diesel specialist. So I did, who changed the fuel filter, but still no fix. So in the end, a quick Google, a hit on this site, this post, and this advice cures my ails. Thanks to y'all for your tips and info. :D